HIV/AIDS, Severe Mental Illness and Homelessness

This is a two-arm randomized controlled trial (RCT) for 308 seriously mentally ill adults (SMI) engaging in risky sexual and/or drug use behavior, comparing a brief HIV primary and secondary prevention intervention \[Skills building and Motivational Interviewing (SB-MI) to Care as Usual (CAU)\]. The study setting is a large urban safety net Medical Center and outcomes will be measured at 3, 6, and 12 months. The SB-MI intervention (3 sessions + booster) was initially developed as the experimental condition in an R34 pilot project which demonstrated its feasibility and promise. For the proposed project, the investigators will recruit a larger sample which includes men and women with and without HIV, from various ethnic and racial groups, sexual orientations and housing arrangements, as well as a range of psychiatric disorders and functional capacities. In this way the investigators can more rigorously demonstrate the promise of SB-MI with SMI. The investigators will also conduct a sub-study after the 6 month follow-up to examine the impact at 12 months of an additional booster session for SB-MI participants. The investigators specific aims are: 1. To examine the effectiveness of a brief, tailored primary and secondary risk reduction strategy to CAU for people with serious mental illness. The desired outcomes include: * Decreased frequency of risk behaviors (number of partners, number of encounters) * Increased use of barrier precautions and IV needle cleaning * Positive changes in information and motivation, as well as risk behaviors * Increased HIV Counseling and Testing for those who do not know their HIV status 2. To examine the effectiveness of a 2nd booster session after the 6 month follow-up for ½ of participants randomized to SB-MI. The primary outcome will be: * Decreased frequency of risk behaviors and increased use of barrier precautions at the 12 month follow-up